1 files changed, 113 insertions, 0 deletions

diff --git a/crates/ra_ide_api/src/references/name_definition.rs b/crates/ra_ide_api/src/references/name_definition.rs
new file mode 100644
index 000000000..4580bc789
--- /dev/null
+++ b/crates/ra_ide_api/src/references/name_definition.rs
@@ -0,0 +1,113 @@
+//! `NameDefinition` keeps information about the element we want to search references for.
+//! The element is represented by `NameKind`. It's located inside some `container` and
+//! has a `visibility`, which defines a search scope.
+//! Note that the reference search is possible for not all of the classified items.
+
+use hir::{
+    db::AstDatabase, Adt, AssocItem, DefWithBody, FromSource, HasSource, HirFileId, MacroDef,
+    Module, ModuleDef, StructField, Ty, VariantDef,
+};
+use ra_syntax::{ast, ast::VisibilityOwner, match_ast, AstNode, AstPtr};
+
+use crate::db::RootDatabase;
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum NameKind {
+    Macro(MacroDef),
+    Field(StructField),
+    AssocItem(AssocItem),
+    Def(ModuleDef),
+    SelfType(Ty),
+    Pat((DefWithBody, AstPtr<ast::BindPat>)),
+    SelfParam(AstPtr<ast::SelfParam>),
+    GenericParam(u32),
+}
+
+#[derive(PartialEq, Eq)]
+pub(crate) struct NameDefinition {
+    pub visibility: Option<ast::Visibility>,
+    pub container: Module,
+    pub kind: NameKind,
+}
+
+pub(super) fn from_pat(
+    db: &RootDatabase,
+    file_id: HirFileId,
+    pat: AstPtr<ast::BindPat>,
+) -> Option<NameDefinition> {
+    let root = db.parse_or_expand(file_id)?;
+    let def = pat.to_node(&root).syntax().ancestors().find_map(|node| {
+        match_ast! {
+            match node {
+                ast::FnDef(it) => {
+                    let src = hir::Source { file_id, ast: it };
+                    Some(hir::Function::from_source(db, src)?.into())
+                },
+                ast::ConstDef(it) => {
+                    let src = hir::Source { file_id, ast: it };
+                    Some(hir::Const::from_source(db, src)?.into())
+                },
+                ast::StaticDef(it) => {
+                    let src = hir::Source { file_id, ast: it };
+                    Some(hir::Static::from_source(db, src)?.into())
+                },
+                _ => None,
+            }
+        }
+    })?;
+    let kind = NameKind::Pat((def, pat));
+    let container = def.module(db);
+    Some(NameDefinition { kind, container, visibility: None })
+}
+
+pub(super) fn from_assoc_item(db: &RootDatabase, item: AssocItem) -> NameDefinition {
+    let container = item.module(db);
+    let visibility = match item {
+        AssocItem::Function(f) => f.source(db).ast.visibility(),
+        AssocItem::Const(c) => c.source(db).ast.visibility(),
+        AssocItem::TypeAlias(a) => a.source(db).ast.visibility(),
+    };
+    let kind = NameKind::AssocItem(item);
+    NameDefinition { kind, container, visibility }
+}
+
+pub(super) fn from_struct_field(db: &RootDatabase, field: StructField) -> NameDefinition {
+    let kind = NameKind::Field(field);
+    let parent = field.parent_def(db);
+    let container = parent.module(db);
+    let visibility = match parent {
+        VariantDef::Struct(s) => s.source(db).ast.visibility(),
+        VariantDef::EnumVariant(e) => e.source(db).ast.parent_enum().visibility(),
+    };
+    NameDefinition { kind, container, visibility }
+}
+
+pub(super) fn from_module_def(
+    db: &RootDatabase,
+    def: ModuleDef,
+    module: Option<Module>,
+) -> NameDefinition {
+    let kind = NameKind::Def(def);
+    let (container, visibility) = match def {
+        ModuleDef::Module(it) => {
+            let container = it.parent(db).or_else(|| Some(it)).unwrap();
+            let visibility = it.declaration_source(db).and_then(|s| s.ast.visibility());
+            (container, visibility)
+        }
+        ModuleDef::EnumVariant(it) => {
+            let container = it.module(db);
+            let visibility = it.source(db).ast.parent_enum().visibility();
+            (container, visibility)
+        }
+        ModuleDef::Function(it) => (it.module(db), it.source(db).ast.visibility()),
+        ModuleDef::Const(it) => (it.module(db), it.source(db).ast.visibility()),
+        ModuleDef::Static(it) => (it.module(db), it.source(db).ast.visibility()),
+        ModuleDef::Trait(it) => (it.module(db), it.source(db).ast.visibility()),
+        ModuleDef::TypeAlias(it) => (it.module(db), it.source(db).ast.visibility()),
+        ModuleDef::Adt(Adt::Struct(it)) => (it.module(db), it.source(db).ast.visibility()),
+        ModuleDef::Adt(Adt::Union(it)) => (it.module(db), it.source(db).ast.visibility()),
+        ModuleDef::Adt(Adt::Enum(it)) => (it.module(db), it.source(db).ast.visibility()),
+        ModuleDef::BuiltinType(..) => (module.unwrap(), None),
+    };
+    NameDefinition { kind, container, visibility }
+}